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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-06-11 10:58:01 +0200 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-06-11 10:58:01 +0200 |
| commit | 4894e4aca82aca927d0404ce61f021f790de4b1e (patch) | |
| tree | bbe0d083829f5858295298f188d885367cf4b1f6 /fs/namespace.c | |
| parent | Input: appletouch - improve finger detection (diff) | |
| parent | Linux 2.6.30 (diff) | |
| download | linux-4894e4aca82aca927d0404ce61f021f790de4b1e.tar.xz linux-4894e4aca82aca927d0404ce61f021f790de4b1e.zip | |
Merge commit 'v2.6.30' into next
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 41196209a906..134d494158d9 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -695,12 +695,16 @@ static inline void mangle(struct seq_file *m, const char *s) */ int generic_show_options(struct seq_file *m, struct vfsmount *mnt) { - const char *options = mnt->mnt_sb->s_options; + const char *options; + + rcu_read_lock(); + options = rcu_dereference(mnt->mnt_sb->s_options); if (options != NULL && options[0]) { seq_putc(m, ','); mangle(m, options); } + rcu_read_unlock(); return 0; } @@ -721,11 +725,22 @@ EXPORT_SYMBOL(generic_show_options); */ void save_mount_options(struct super_block *sb, char *options) { - kfree(sb->s_options); - sb->s_options = kstrdup(options, GFP_KERNEL); + BUG_ON(sb->s_options); + rcu_assign_pointer(sb->s_options, kstrdup(options, GFP_KERNEL)); } EXPORT_SYMBOL(save_mount_options); +void replace_mount_options(struct super_block *sb, char *options) +{ + char *old = sb->s_options; + rcu_assign_pointer(sb->s_options, options); + if (old) { + synchronize_rcu(); + kfree(old); + } +} +EXPORT_SYMBOL(replace_mount_options); + #ifdef CONFIG_PROC_FS /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) @@ -1073,9 +1088,7 @@ static int do_umount(struct vfsmount *mnt, int flags) */ if (flags & MNT_FORCE && sb->s_op->umount_begin) { - lock_kernel(); sb->s_op->umount_begin(sb); - unlock_kernel(); } /* |